$\dfrac{6}{4} - \dfrac{4}{3} = {?}$
Answer: $ = {\dfrac{6 \times 3}{4 \times 3}} - {\dfrac{4 \times 4}{3 \times 4}} $ $ = {\dfrac{18}{12}} - {\dfrac{16}{12}} $ $ = \dfrac{{18} - {16}}{12} $ $ = \dfrac{2}{12}$